51778221777 has 6 divisors (see below), whose sum is σ = 74790764802. Its totient is φ = 34518814512.

The previous prime is 51778221769. The next prime is 51778221839. The reversal of 51778221777 is 77712287715.

51778221777 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 30649855041 + 21128366736 = 175071^2 + 145356^2 .

It is not a de Polignac number, because 51778221777 - 2³ = 51778221769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51778221977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2876567868 + ... + 2876567885.

It is an arithmetic number, because the mean of its divisors is an integer number (12465127467).

Almost surely, 2^51778221777 is an apocalyptic number.

It is an amenable number.

51778221777 is a deficient number, since it is larger than the sum of its proper divisors (23012543025).

51778221777 is a wasteful number, since it uses less digits than its factorization.

51778221777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5753135759 (or 5753135756 counting only the distinct ones).

The product of its digits is 2689120, while the sum is 54.

The spelling of 51778221777 in words is "fifty-one billion, seven hundred seventy-eight million, two hundred twenty-one thousand, seven hundred seventy-seven".